“The Door to Hell” is the name given to a natural gas field in Derweze, Turkmenistan, which has been burning since 1971 when it was ignited by Soviet scientists who expected it to burn out within days.
In 1971 Soviet geologists were drilling in the area when they drilled through into a huge underground cavern. The roof of the cavern collapsed under the drilling rig leaving a hole about 230 feet across and 66 feet deep. Methane gas was escaping into the atmosphere through the large crater. The geologists decided to light the gas on fire expecting it to burn out in a few days. Now, over 40 years later, the gas is still burning. The name “Door to Hell” was given to the field by locals.